Segmental Vessel Ligation Research Articles

Editorial Comment

The authors 1 Kopp R.P. Liss M.A. Mehrazin R. et al. Analysis of renal functional outcomes after radical or partial nephrectomy for renal masses ≥7 cm using the RENAL score. Urology. 2015; 86: 312-320 Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar should be congratulated for this significant contribution to the partial nephrectomy (PN) literature. The present study was a retrospective analysis evaluating renal function outcomes after open PN compared with radial nephrectomy (RN) stratified by RENAL sum for renal masses >7 cm (T2RMs). As expected, the ΔeGFR was greater in RN (−19.7) vs PN (−11.9) and the de novo chronic kidney disease was significantly delayed in PN verses RN. Interestingly, they demonstrated equivalent renal function outcomes for PN and RN if RENAL score ≥10, whereas PN was associated with greater complication rates. To understand renal function after PN, baseline renal function, ischemic injury, amount of healthy tissue removed, and reconstructive injury (renorrhaphy) must all be considered. Cold and warm ischemia median times were 48 and 24 minutes, respectively, which appear to be in the acceptable ranges for T2RMs. Maximally preserving renal function would require small resection margins and atraumatic reconstruction techniques. Significant injury from cortical renorrhaphy can occur with even small renal masses. A recent study attributed a 12% loss in ipsilateral renal volume to cortical renorrhaphy on adjusted analysis. 2 Bahler C.D. Dube H.T. Flynn K.J. et al. Feasibility of omitting cortical renorrhaphy during robotic partial nephrectomy: a matched analysis. J Endourol. 2015; 29: 548-555 Crossref PubMed Scopus (48) Google Scholar Reconstructive injury is thought to be due to ligation of segmental vessels in addition to strangulated parenchyma, which has been shown to be worse with more central tumors (higher RENAL score). 3 Simmons M.N. Hillyer S.P. Lee B.H. et al. Nephrometry score is associated with volume loss and functional recovery after partial nephrectomy. J Urol. 2012; 188: 39 Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar Analysis of Renal Functional Outcomes After Radical or Partial Nephrectomy for Renal Masses ≥7 cm Using the RENAL ScoreUrologyVol. 86Issue 2PreviewTo determine if partial nephrectomy (PN) confers a renal functional benefit compared to radical nephrectomy (RN) for clinical T2 renal masses (T2RM) when adjusting for tumor complexity characterized by the RENAL nephrometry score. Full-Text PDF ReplyUrologyVol. 86Issue 2PreviewThe use of partial nephrectomy (PN) for larger masses has increased in recent years, primarily driven by the increasing experience with the procedure on the whole, emerging data suggesting oncologic equivalence to radical nephrectomy, and a growing awareness of the potential deleterious long-term consequences of nephron loss and chronic renal insufficiency.1 PN for larger masses is not without controversy, given increased risk of procedure-specific complications and doubts about the renal functional benefit of nephron-sparing surgery for larger masses. Full-Text PDF ErratumUrologyVol. 94PreviewIn the Editorial Comment by Thomas Allen Gardner, Clinton D. Bahler, and Paul T. Gellhaus to the August 2015 article “Analysis of Renal Functional Outcomes After Radical or Partial Nephrectomy for Renal Masses ≥7 cm Using the RENAL Score” (Urology 2015;85:319-320), the commenting editors regret that the commenting editor name Paul T. Gellhaus was misspelled. Full-Text PDF

Anterior surgery for adolescent idiopathic scoliosis

Anterior open scoliosis surgery using the dual rod system is a safe and rather effective procedure for the correction of scoliosis (50-60%). Thoracic hypokyphosis and rib hump correction with open anterior rather than posterior instrumentation appear to be the better approaches, although the latter is somewhat controversial with current posterior vertebral column derotation devices. In patients with Risser grade 0, hyperkyphosis and adding-on may occur with anterior thoracic spine instrumentation. Anterior thoracoscopic instrumentation provides a similar correction (65%) with good cosmetic outcomes, but it is associated with a rather high risk of instrumentation (pull-out, pseudoarthrosis) and pulmonary complications. Approximately 80% of patients with adolescent idiopathic scoliosis (AIS) curves of >70° have restrictive lung disease or smaller than normal lung volumes. AIS patients undergoing anterior thoracotomy or anteroposterior surgery will demonstrate a significant decrease in percentage of predicted lung volumes during follow-up. The thoracoabdominal approach and thoracoscopic approach without thoracoplasty do not produce similar changes in detrimental lung volume. In patients with severe AIS (>90°), posterior-only surgery with TPS provides similar radiographic correction of the deformity (44%) with better pulmonary function outcomes than anteroposterior surgery. Vascular spinal cord malfunction after segmental vessel ligation during anterior scoliosis surgery has been reported. Based on the current literature, the main indication for open anterior scoliosis instrumentation is Lenke 5C thoracolumbar or lumbar AIS curve with anterior instrumentation typically between T11 and L3.

Relevance of the anatomical location of the Adamkiewicz artery in spine surgery

The aim of this study was to describe the preoperative topography of the Adamkiewicz artery and the blood supply of the lumbosacral spinal cord in patients who underwent spinal surgery. The relevance for anterior approaches of the thoracolumbar spine was then analyzed. One hundred consecutive spinal angiographies were reviewed. Surgical indications were: 26 vertebrectomies, 30 anterior fusions in fractures, 13 malunions, 16 anterior releases in scoliosis, 11 pedicle subtraction osteotomies and 4 thoracic disc hernias. The level and the side of the Adamkiewicz artery and the presence of additional radiculomedullary arteries were determined. Modifications of surgical planning owing to the Adamkiewicz artery were analyzed. The Adamkiewicz artery was always located between T8 and L3, at T9 or T10 in 50%, and coming from the left side in 75% of the cases. Additional radiculomedullary arteries were found in 43% of the cases. A concordance between the topography of the Adamkiewicz artery and the planned surgical approach was noted in 15%, which led to ten side changings and three modifications of surgical technique with segmental vessel preservation. An ischemic syndrome of the anterior spinal cord did not occur. Spinal cord ischemia is rarely reported after segmental vessel ligation. Spinal angiography allows determining the topography of the Adamkiewicz artery safely. If the planned surgical approach is located at the same level, a contralateral approach or selective surgical techniques without vessel ligation could avoid possible damage to the Adamkiewicz artery if the pathology does not dictate the side and the extent of the surgical approach.

Segmental vessel ligation in patients undergoing surgery for anterior spinal deformity

Segmental vessel ligation during anterior spinal surgery has been associated with paraplegia. However, the incidence and risk factors for this devastating complication are debated. We reviewed 346 consecutive paediatric and adolescent patients ranging in age from three to 18 years who underwent surgery for anterior spinal deformity through a thoracic or thoracoabdominal approach, during which 2651 segmental vessels were ligated. There were 173 patients with idiopathic scoliosis, 80 with congenital scoliosis or kyphosis, 43 with neuromuscular and 31 with syndromic scoliosis, 12 with a scoliosis associated with intraspinal abnormalities, and seven with a kyphosis. There was only one neurological complication, which occurred in a patient with a 127 degrees congenital thoracic scoliosis due to a unilateral unsegmented bar with contralateral hemivertebrae at the same level associated with a thoracic diastematomyelia and tethered cord. This patient was operated upon early in the series, when intra-operative spinal cord monitoring was not available. Intra-operative spinal cord monitoring with the use of somatosensory evoked potentials alone or with motor evoked potentials was performed in 331 patients. This showed no evidence of signal change after ligation of the segmental vessels. In our experience, unilateral segmental vessel ligation carries no risk of neurological damage to the spinal cord unless performed in patients with complex congenital spinal deformities occurring primarily in the thoracic spine and associated with intraspinal anomalies at the same level, where the vascular supply to the cord may be abnormal.

Reduction of Vertebral Blood Flow by Segmental Vessel Occlusion: An Intraoperative Study Using Laser Doppler Flowmetry

During anterior spinal surgery, vertebral perfusion was assessed by laser Doppler flowmetry. Blood flow changes were assessed after unilateral ligation and contralateral compression of the segmental vessels. To assess the influence of unilateral and bilateral segmental vessel occlusion on vertebral blood flow. During anterior spinal surgery, segmental vessels are frequently being ligated. The reduced blood supply to the vertebrae may impair intervertebral fusion, and the decreased spinal cord perfusion may lead to ischemic myelopathy. To our knowledge, this is the first in vivo study to investigate vertebral blood flow. METHODS.: There were 10 patients who underwent anterior release for adult idiopathic scoliosis (n = 6), Scheuermann disease (n = 3), and posttraumatic kyphosis (n = 1). A high-power laser Doppler flowmeter was used to assess vertebral blood flow. Measurements were performed in 19 thoracic and 4 lumbar vertebrae (n = 23) after unilateral segmental vessel ligation and additional temporary digital compression of the contralateral vessels. Initial mean blood flow was 49.1 +/- 27.6 arbitrary units, and all signals were pulsatile. The blood flow decreased by a mean of 8% after unilateral ligation of the segmental vessels. With additional compression of the contralateral vessels, the signal heights decreased significantly by 54% (mean 18.3 +/- 7.8 arbitrary units, P = 0.00003), and a loss of the pulsatile pattern was observed in 75% of the vertebrae. On release of digital compression, the signal height as well as the pulsatility promptly returned. Unilateral ligation of segmental vessels led only to a slight decrease of the vertebral blood flow. Future studies may show whether sparing the segmental vessels during anterior fusion enhances bone graft incorporation, thus decreasing the rate of pseudarthrosis. According to clinical data, the risk of neurologic injury through unilateral ligation is negligible. Bilateral segmental vessel occlusion markedly reduced vertebral bloodflow. Therefore, when treating patients with a higher neurologic risk or in revision cases, the surgeon should always consider sparing the segmental vessels.

Cord Monitoring Changes and Segmental Vessel Ligation in the “At Risk” Cord During Anterior Spinal Deformity Surgery

Retrospective analysis of all cases of anterior spinal deformity surgery that had intraoperative spinal cord monitoring (somatosensory-evoked potentials, SSEPs). The prime purpose of this study was to determine the incidence of significant SSEP changes in patients undergoing anterior spinal deformity surgery. A secondary objective was to ascertain if patients with "cords at risk" were more likely to produce significant intraoperative SSEP changes and what proportion of these changes resulted in postoperative neurological deficit. There is anecdotal evidence to suggest that patients with intraspinal abnormalities are at greater risk of postoperative neurological deficit after spinal deformity surgery. To date, there have been no studies detailing this risk and how it relates to the type of surgery performed. This is a question of increasing relevance with the modern trend towards more anterior scoliosis correction and instrumentation. Recent reports have suggested a low incidence of neurological complication with anterior deformity procedures. There is controversy as to whether SSEP monitoring is required for these anterior procedures and whether soft clamping of segmental vessels before their division is a necessary precaution. This study is a chart review of all patients who had an anterior deformity operation between 1990 and 2001. Those patients who had a complete data set (preoperative magnetic resonance imaging scan, patient and procedural documentation, and adequate intraoperative SSEP traces) were included in this study. A significant SSEP change was correlated with the type of procedure performed, whether that patient had a "cord at risk" (CAR) and the degree of postoperative neurological deficit if present. During the study period, 871 patients underwent elective anterior spinal deformity surgery. Ninety five (11%) patients had intraspinal abnormalities on magnetic resonance imaging. From this group, 27 (3%) were termed CAR. Twenty six (3%) patients had significant change in the intraoperative SSEP monitoring. Seventeen (2% total) occurred in the CAR group and nine (1% of total) in the normal cord group. There were five patients (0.6%) with significant postoperative neurological deficits, four (0.5%) in the CAR group, and one (0.1%) in the normal cord group. These patients had also demonstrated changes in their SSEPs. The sensitivity of SSEP monitoring for the whole series was 100%, specificity 97.5%, the positive predictive value was 19% and the negative predictive value was 100%. The CAR group was significantly more likely to have significant SSEP changes during any operation and was more likely to have postoperative paresis. Patients with identified cords at risk should undergo spinal cord monitoring (SSEP) if they undergo anterior spinal deformity surgery. Soft clamping of segmental vessels is indicated with cord monitoring to prevent the risk of postoperative neurological sequelae.

ANTERIOR SURGERY IN THE THORACIC AND LUMBAR SPINE

Therapeutic modalities for disorders of the pediatric spine must include video-assisted thoracoscopy. The endoscopic approach to the spine has involved an evolutionary approach. What began as an isolated drainage of a vertebral abscess has continued as a method of single diskectomy, release of the anulus fibrosus with or without ligation of segmental vessels, rib resection for costoplasty, rib harvesting for intervertebral fusion and, most recently, insertion of correctional implants with or without spinal fusion. Video-assisted thoracoscopic surgery offers the potential to decrease surgical morbidity associated with traditional open procedures. The ability of video-assisted thoracoscopic surgery to achieve spinal release and the results of early outcomes and cost are comparable to those of open thoracotomy. The improvement in video technology with multichip cameras has significantly improved and enhanced the ability to identify structures in the chest through small incisions (portals). This technology allows spine surgeons to perform surgical intervention comparable to thoracotomy. Instead of using a 9- to 12-inch incision, four to five portals of approximately 2 cm are used; thus, the cosmetic efects of the scoliosis surgery are enhanced. The potential benefits of this procedure include diminished postoperative pain, decreased length of hospitalization, increased wound care, and early return to prehospital activities.

83. Neurological deficit from a purely vascular etiology after anterior thoracolumbar fusion of the spine

HYPOTHESIS: Our objective is to report on neurological deficit from a purely vascular insult to the spinal cord occurring after anterior thoracolumbar spinal surgery that did not involve additional correction. The study by Winter et.al reports that there is a minimal risk with unilateral ligation of segmental vessels in the thoracolumbar spine.

Operative Treatment of Specific and Unspecific Spondylitis of the Thoracic Spine

Objective Prevention or cure of nerve root compression. Radical debridement and removal of inflammatory focus. Restitution of stability in the presence of radiologic evidence of vertebral body destruction. Restoration of profile of spinal column. Indications Spondylodiscitis complicated by neurologic deficits. Spondylitis with formation of abscess, progressive destruction of vertebral body and imminent instability. Contraindications Poor general health due to various illnesses. Surgical Technique Transthoracic approach to the spine (T2–T10). Transpleural retroperitoneal approach to the lumbar spine (T11–T12). Ligation of segmental vessels. Radical removal of inflamed tissue. Insertion of a MOSS® titanium cylinder filled with autogenous cancellous bone or rib according to Stolze & Harms. Additional anterior or posterior instrumentation to improve stability. Results Between October 1995 and November 2000, an anterior vertebral body replacement was performed in 19 patients (three women, 16 men, average age 63 [43–79] years) for spondylitis of the thoracic spine. In 14 of these patients, an additional anterior or posterior instrumentation was done. Follow-up after an average of 23 [7–66] months in 16 patients. Three patients passed away in the meantime. Neurologic status classified according to Frankel et al. Preoperative deficits found in 11/19 patients. At the time of follow-up, nine patients had improved by at least one grade. Since no scoring system for results of treatment for spondylitis could be found in the literature, we developed our own score that showed an improvement from 13 points preoperatively to 37 points postoperatively. Healing of spondylitis could be confirmed clinically and radiologically in all patients followed up.

Thoracoscopic discectomy and fusion in an animal model: safe and effective when segmental blood vessels are spared.

Disc-endplate excision and spine fusion were compared in animals randomly assigned to segmental vessel-spared and segmental vessel-ligated groups in an in vivo goat model of anterior spine discectomy and fusion using thoracoscopic techniques. To compare safety and completeness of disc and endplate excision, and to perform a histologic and biomechanical comparison between fusion masses when the segmental vessels are spared and when they are ligated using thoracoscopic techniques. SUMMARY OFF BACKGROUND DATA: Because thoracoscopy is relatively new and technically demanding, many surgeons ligate the segmental blood vessels to enhance spine exposure and limit the risk of injury during discectomy and fusion. Although rare, spinal cord compromise secondary to segmental vessel ligation has been reported. This study was divided into two phases. In Phase 1, 10 mature goats were randomly assigned to either the segmental vessel-ligated or the segmental vessel-spared group. Disc and endplate excision was performed at six consecutive thoracic levels in each animal (30 levels per group). The animals were killed, and the depth of disc excision was measured in the transverse and sagittal planes. The vertebral bodies then were separated through the disc space; photographic images of the endplates were digitized, and the area of endplate excision was calculated. In Phase 2, 12 mature goats were randomly assigned to the segmental vessel-ligated or vessel-spared group, and five noncontiguous thoracic segments were fused using autologous iliac crest graft. At 4 months the animals were killed, and the spines were harvested. At each disc level, the three-dimensional rotational and translational motions were analyzed and histomorphometric analysis was performed. Phase 1: Each animal survived the operative procedure, and no surgical complications occurred. No difference was found between vessel-ligated and vessel-spared groups in operative time (21.8 vs 22.7 minutes per disc), blood loss (97 vs 159 mL), or transverse (81% vs 74%) or sagittal (85% vs 85%) disc excision. The total area of endplate excision was 70% in the vessel-ligated group and 67% in the vessel-spared group (P > 0.1). Phase 2: Biomechanical testing demonstrated no difference in stiffness of the fused segments between the two groups in flexion-extension or axial rotation. However, greater flexibility in lateral bending was found in the specimens whose vessels were ligated (P < 0.05). The percentage of trabecular bone volume was similar between the two groups. The segmental vessels in the thoracic spine can be effectively spared without injury during disc excision and fusion. Although slightly more disc area was excised with ligation of the vessels, this was not statistically significant, and the fusion mass was similar between the two groups. Sparing the segmental vessels may provide blood supply that aids fusion mass, and the result may be greater spine stiffness in the coronal plane. Sparing the segmental vessels during thoracoscopic anterior disc excision and fusion can be safe. It should be considered in patients with a high risk for neurologic injury because of decreased spinal cord perfusion in revision surgery, severe kyphosis, congenital anomalies. Because the neurologic risk of vessel ligation has not been clearly established for idiopathic scoliosis, the surgeon will have to consider the risk-benefit ratio of adopting these methods when deciding not to ligate vessels in these patients.

DOES THE ABSORBABLE FIBRIN ADHESIVE BANDAGE FACILITATE PARTIAL NEPHRECTOMY?

To evaluate the ability of the absorbable fibrin adhesive bandage (AFAB), a prototype product comprising lyophilized fibrinogen and thrombin on a VicrylTM mesh backing, to seal the collecting system and control bleeding after partial nephrectomy. Growing female pigs (n = 18) underwent left nephrectomy and a 40% (by length) right lower pole partial nephrectomy. One of three treatments was immediately applied: Conventional-closure of the collecting system, ligation of visible segmental vessels, application of SurgicelTM with bolstering sutures to the renal capsule; AFAB-application of up to two 4 x 4-inch AFABs held under pressure for 60 seconds; Placebo-application of a hemostatically inert VicrylTM bandage, visually identical to the AFAB. Blood loss and ischemic and total operative times were recorded, and abdominal computerized tomography (CT) was performed on postoperative day 6. Animals were sacrificed at 6 weeks to evaluate the remaining renal mass histologically. Compared with conventional therapy, use of the AFAB resulted in significantly less bleeding (13 versus 68 ml., p <0.001) and lower operative (7.2 versus 16.3 minutes, p <0.001) and ischemic times (3.4 versus 7.8 minutes, p <0.001). Estimated blood loss in the placebo bandage group was dramatically higher (357 ml., p <0.001). Postoperative CT and histological sectioning suggested that the AFAB produces a stable, durable clot and that healing is at least as successful as with conventional treatment. Use of the AFAB facilitated performance of partial nephrectomy by reducing blood loss and ischemic and total operative times. The AFAB appears equivalent to conventional surgery in its ability to seal the collecting system.

DOES THE ABSORBABLE FIBRIN ADHESIVE BANDAGE FACILITATE PARTIAL NEPHRECTOMY?

Purpose: To evaluate the ability of the absorbable fibrin adhesive bandage (AFAB), a prototype product comprising lyophilized fibrinogen and thrombin on a VicrylTM mesh backing, to seal the collecting system and control bleeding after partial nephrectomy.Materials and Methods: Growing female pigs (n = 18) underwent left nephrectomy and a 40% (by length) right lower pole partial nephrectomy. One of three treatments was immediately applied: Conventional–closure of the collecting system, ligation of visible segmental vessels, application of SurgicelTM with bolstering sutures to the renal capsule; AFAB–application of up to two 4 × 4-inch AFABs held under pressure for 60 seconds; Placebo–application of a hemostatically inert VicrylTM bandage, visually identical to the AFAB. Blood loss and ischemic and total operative times were recorded, and abdominal computerized tomography (CT) was performed on postoperative day 6. Animals were sacrificed at 6 weeks to evaluate the remaining renal mass histologically.Results...

Reversible Ischemic Myelopathy During Scoliosis Surgery: A Possible Role for Intravenous Lidocaine

An unusual and previously unreported case of partially reversible ischemic myelopathy after limited unilateral segmental vessel ligation during scoliosis surgery is described. Intravenous lidocaine, used intraoperatively for its vasoactive properties, induced an immediate and meaningful recovery of neurologic function. The conceptual and pharmacologic basis for this intervention is discussed in view of this exceedingly rare complication of segmental vessel ligation.

VIDEO-ASSISTED THORACOSCOPY

New therapeutic modalities for disorders of the pediatric spine must include video-assisted thoracoscopy. The endoscopic approach to the spine has involved an evolutionary approach. What began as an isolated drainage of a vertebral abscess was continued as a method of single discectomy; release of the annulus fibrosis with or without ligation of segmental vessels; rib resection for costoplasty; rib harvesting for intervertebral fusion; and most recently, insertion of correctional implants and fusion.

Paraplegia resulting from vessel ligation.

This is a retrospective review of clinical records for evidence of paraplegia specifically resulting from segmental vessel ligation during anterior spinal surgery. To determine the precise risk rate, and to potentially identify risk factors. Although many authors have alluded to this risk, the exact risk rate and risk factors have never been identified. All patients having an anterior approach involving T1-L3 were reviewed. The two reviewers were not involved in any of the surgeries. The 1197 cases were consecutive from 1967 to 1991. There were no paralyses. There would appear to be virtually no risk to segmental vessel ligation provided: 1) vessel ligation is unilateral, 2) done on the convexity of a scoliosis, 3) ligated at midvertebral body level, and 4) hypotensive anesthesia is avoided. Soft clamping with somatosensory-evoked potential monitoring does not appear justified.

Splenic trauma in children and techniques of splenic salvage.

AbstractThe increased risk of sepsis after splenectomy applies to any age for any reason. Splenic injuries consequently are now managed when possible by salvage procedures or nonoperative observation. This is not without controversy and in an attempt to define these injuries more appropriately and so predict optimal management, a quantitative and qualitative classification of presence and severity is presented, based on computed tomography. Type I injuries consist of localized capsular disruption or subcapsular hematomas, without significant parenchyma injury. Type II injuries consist of single or multiple capsular disruptions, with parenchymal injury that does not extend into the hilum or involve major vessels, with or without intraparenchymal hematoma. Type III injuries consist of deep fractures, single or multiple, that extend into the hilum and involve major vessels. Type IV injuries are those in which the spleen is completely shattered, fragmented, or separated from its normal blood supply. Added to this is the subclassification A for splenic injuries without associated intra‐abdominal injuries; B for splenic injuries with associated intra‐abdominal injuries, B1 for injuries involving a solid viscus, B2 for injuries involving a hollow viscus; and E for splenic injuries with associated extra‐abdominal injuries.Surgical techniques for splenic salvage consist of the application of topical hemostatic agents or omentum with or without simple capsular sutures, direct suturing of capsule and parenchyma, ligation of individual or segmental vessels, partial splenectomy, application of an absorbable net or ladder, and large entire organ through‐ and‐through sutures. These techniques are illustrated and alternatives to salvage are discussed.